The invention relates to a device including a circuit for actuating electric functional elements having at least two physically separate actuating modules.
Such a device can be used to trigger electric functions selectively from one or the other actuating module and hence from different locations. Each actuating module has actuating elements for triggering the electric functions, with those actuating elements of different actuating modules which are provided for triggering the same electric function being connected in parallel with one another.
Such devices are used in motor vehicles, for example, so that particular electric devices in a motor vehicle, such as a car radio or a window lifter, can be operated both by the driver and by the passenger. Two physically separate actuating modules are provided for triggering the electric functions. One actuating module is positioned within reach of the driver and the other is positioned within reach of the passenger.
Problems arise with such circuits if the electric actuating modules are each provided for triggering a plurality of electric functions and accordingly have a plurality of actuating elements, each of which is associated with a particular electric function. Precautions are required to deal with the situation when different electric functions which are not meant to be performed simultaneously are triggered simultaneously as a result of incorrect operation of the actuating elements. Such a situation arises, for example, if the driver of a motor vehicle activates a particular electric system while the passenger simultaneously triggers an actuating element used to deactivate the system.
This problem is frequently solved in known electric circuits by giving priority to one of the actuating elements in the event of different actuating elements being operated simultaneously. The electric circuit is designed so that, when a plurality of actuating elements are operated simultaneously, only that electric function which is associated with the actuating element having the highest priority is triggered. However, such circuits have the drawback that, to prevent contradictory control commands which may result from incorrect actuation, some of the information contained in the electric signals triggered by the incorrect actuation is suppressed. This is because only the signals which have been triggered by actuation of the actuating element having the highest priority are processed. All other signals are masked out or suppressed.
In other circuit arrangements, the xe2x80x9cprioritizationxe2x80x9d described previously is avoided by allocating each actuating element a dedicated signal line. In such a case, an appropriate control unit can evaluate the signals coming from the individual signal lines individually and can trigger the appropriate electric functions on the basis of this evaluation. However, these known devices have the drawback that they require a very high level of circuit complexity, particularly in cases in which each actuating module has a relatively large number of actuating elements associated with it.
Problems of the type described above may additionally arise if the actuating modules are incorporated in a circuit along with other manually triggerable electric units.
U.S. Pat. No. 4,801,812 (incorporated by reference herein) discloses an electric arrangement for actuating a window lifter on the passenger side of a motor vehicle, in which raising and lowering of the window can be selectively triggered both from an actuating device on the driver""s side and from an actuating device on the passenger side; in which each of these two actuating devices has two switch positions for raising and lowering the window; and in which each of the two switch positions has an associated defined electric code which can be used to identify the respective electric function performed (raising or lowering of the window on the passenger side).
Accordingly, it is an object of the present invention to provide a device for actuating electric functions which uses simple means to permit extensive evaluation of the control commands produced by operation of the actuating elements in the different actuating modules.
According to the present invention a device for actuating electric functional elements having at least two physically separate actuating modules is provided. The device includes defined electric functions that may be selectively triggered from one or the other actuating module A1-AM). Each of the actuating modules A1-AM) has at least two electric actuating elements (1-N) for triggering different electric functions, and those actuating elements (1-N) of different actuating modules A1-AM) which are provided for triggering the same electric function are connected in parallel with one another, wherein the actuating elements (1 to N) provided for triggering the same electric function have a respective electric assembly (B1-BN) arranged in parallel with them which may be used to produce an electric code which is characteristic of the electric function to be triggered, wherein the electric actuating elements (1-N) within an actuating module A1-AM) are respectively connected in series with one another.
Accordingly, the electric actuating elements within an actuating module are respectively connected in series, the actuating elements associated with a particular electric function on different actuating modules having a respective electric assembly connected in parallel with them which has an electric code which is characteristic of the electric function.
The inventive solution has the advantage that, with the actuating elements in each module in a simple series circuit, evaluating the electric code makes it possible, at any time, to clearly establish which actuating elements have been actuated to trigger a particular electric function. This is because any actuation of an actuating element influences the electric code of the electric assembly arranged in parallel with the appropriate actuating element in a defined manner. Evaluating the code signals in a suitable evaluation unit thus allows the appropriate electric function to be performed either immediately or with a delay or else not at all, depending on the state of the system to be driven. Prioritization of the individual switching functions, which is always associated with information losses, is not necessary.
If a plurality of electric functions are triggered simultaneously in the inventive device (e.g. by different operators on different actuating modules), the evaluation unit records corresponding changes to the associated electric codes. The programming of the evaluation unit is then used to decide whether the individual electric functions are being performed simultaneously, in succession or only in part.
In this context, the different electric functions which may be controlled by the individual actuating elements of the actuating modules may be both associated with various electric functional elements and may affect different functions of one and the same functional element, such as in the case of two actuating elements for changing the volume of a car radio to a higher or lower volume.
In this context, a suitable electric code may easily be produced by virtue of the electric assembly being one or more passive electric components having an electric value which is characteristic of the respective electric function. Thus, the electric assembly may be formed by a nonreactive resistor whose resistance value is characteristic of the electric function to be triggered. By way of example, a resistor having a resistance value of 10 ohms is used for a first electric function, a resistor having a resistance value of 100 ohms is used for a second electric function, a resistor having a resistance value of 1000 ohms is used for a third electric function etc.
Instead of a simple nonreactive resistor, a complex resistor or a frequency-dependent resistor (e.g., an inductor or a capacitor), and also a voltage-dependent or current-dependent resistor, a diode circuit, in particular a zener diode circuit, or else a voltage reference circuit are suitable as alternatives. In addition, the electric components may also be combined with one another to form an appropriate electric assembly.
Alternatively, the electric assembly for producing a characteristic electric code may be an active electric circuit, for example a circuit for producing a characteristic pulse train and/or a characteristic frequency. Naturally, a frequency mix or characteristic amplitude modulation are also suitable in this regard.
In one preferred embodiment of the invention, all the actuating modules with their electric actuating elements and the associated electric assemblies are incorporated into an integrated electric circuit supplied with current via two external electric connections. This produces a particularly simple circuit design for the device.
The electric assemblies used for assigning the individual actuating elements to particular electric functions are preferably arranged in the actuating modules themselves. In this context, the connection of the electric assemblies in parallel with the appropriate electric actuating elements means that only one corresponding electric assembly is required per electric function to be controlled. The electric assembly is accordingly arranged in one of the actuating modules from which the appropriate electric function may be triggered using an actuating element.
In this case, the electric assemblies are preferably distributed over the actuating modules such that an electric current may flow through the device meanderingly when the electric actuating elements are fully off, the current passing through all of the electric assemblies, and, in this context, each leg of the meandrous current path running through all the (parallel-connected) actuating modules. Such a circuit arrangement may be produced, for example, by alternately assigning each of the electric assemblies used for producing a characteristic electric code to one of the actuating modules whose actuating elements form an outer edge of the parallel circuit.
This embodiment of the invention allows simple monitoring of the lines of the circuit arrangement and, in particular, reliable detection of line breakage or plug contact interruption when the electric actuating elements are fully off. This is because, when the actuating elements are fully off, the current may flow through the electric assemblies connected in parallel therewith and may thus meander through the entire circuit arrangement.
In this context, the two external electric connections form the two end points of the meandrous current path, for which purpose the two connections are connected to a respective actuating element which is at a maximum distance (in relation to the flow of current) from the connections of the associated, parallel-connected electric assembly.
The electric actuating elements may be formed both by electric switches and by pushbutton switches or other suitable switching elements.
The inventive device may be used, in particular, in motor vehicles, one of the actuating modules being able to be arranged in the steering wheel of the vehicle in order to allow the driver to reach it easily.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and are not restrictive of the invention as claimed.